Arthropod ectoparasites commonly infecting warm-blooded animals include ticks, mites, lice, fleas, blowfly, the ectoparasite Lucilia sp. of sheep, biting insects including keds (Melophagus ovinus) and migrating dipterous larvae such as Hypoderma sp. and Dermatobia in cattle, Gastrophilus in horses and Cuterebra sp. in rodents.
Metaflumizone is useful for the prevention and control of infestation by ectoparasites in warm-blooded animals. Topical administration of this active is a preferred method for administering this compound.
To provide suitable protection against ectoparasitic infection or infestation in warm-blooded animals it is desirable to use a semi-solid topical formulation having a relatively high loading of metaflumizone. Such a formulation has the effect of providing a formulation that is easy to apply, good spreading over skin, and avoids run-off. However, it is often difficult to formulate such compositions with stability of the active while maintaining the desirable characteristics of a semi-solid composition. Metaflumizone is one of several useful insecticidal agents which have found particular application for the control of fleas and ticks on animals, particularly companion animals such as dogs, cats and horses. It is particularly advantageous in that it can provide 4-6 weeks of protection from fleas and ticks in companion animals, yet it would still be desirable to formulate it so that a semi-solid application could be applied to protect the subject animal while avoiding the possibility of ingestion by the subject animal and/or run-off and waste of the active. Nonetheless, formulations are difficult due to the insolubility of metaflumizone in many solvents, and its instability in the presence of primary alcohols.
It is an object of the present invention to provide a semi-solid composition for topical administration which comprises a relatively high loading of metaflumizone and which will provide protection from ectoparasitic infestation for a suitable period of time.
It is also an object of the present invention to provide a method for preventing or treating ectoparasitic infestation in warm-blooded animals for prolonged periods of time.
It is another object of this invention to reduce or control the proliferation of such insects in warm-blooded animals for prolonged periods of time by a topically applied active, with the formulation being mild and gentle enough to avoid adverse skin reactions upon administration, yet with the ability to be retained in the animal's skin and/or coat over the time needed for protection.
These and other objects of the present invention will become more apparent from the description thereof set forth below and the appended claims.